From text I sent to Sterophile

I have been a subscriber for about 15 years. In that time I have
learned, and tried to put in practice, good room treatment techniques. I
use test CD's and a sound meter to aid in placement and I treat all the
room hot spots like first order reflection, echo flutter and deaden the
area behind my head (my Triangle Celius speakers sounds their best in a
spot that forces me to the rear wall- I have an odd room). What confuses
me is the double speak on tone controls and equalizers as well as
exactly which test tones I should use when running the tests.

On equalizers/tone controls. I can't count how many times I have read
that these are either the bane of our collective electronic existence or
a necessary tool to help make some recordings sound right (specifically
tone controls). On equalizers I read that they induce too many problems
but your magazine has recommended several of them (all in the digital
domain I believe).

In my room I have several strong nodes below 300hz (as do most people I
am sure). I have a small dent at 50hz, huge plus ups at 60hz and 120hz
and a dip at about 250hz (Here is where the test tone confusion comes
in. With warble tones the aberrations are far lower. With straight tones
I have a 16db shift from 120hz to 250hz - with warble tones the shift is
about 5db. Which am I to use? Seems to me warble tones are more
effective because the approximate the changes that occur in music?).
After studiously using my test gear/tones, set up programs, several
suggestions from professional sources (read in your mag and others) as
well as installing some room treatment (albeit none for bass control) I
am left with the predicament described. As far as I can tell room
treatments, designed to help in the low end, are not discriminate
enough. While they will tame my hot spots they will also negatively
affect my dips(?). Using a bass tone control won't work for basically
the same reason. At the end of the day (which I assure you is a grossly
understated metaphor) I decided to try a cheap 10 band EQ I had on hand
(I would try the digital products but they are way too expensive).
Utilizing the EQ and other associated items I was able to smooth out the
bumps, in both directions, to a very significantly measurable degree.
Now here's the rub. When I asked my daughter to help me A/B the
difference (which is easy with an EQ - one button) I had to work at
hearing the difference - more often than not. (I should note that I
could go flat to 40hz and only 3db down at 31.5hz). While I was able to
discern the difference on some recordings (bass notes ended sooner - no
bloat) it was not a startling difference. As such is it "better" that I
use the EQ to settle the bloat or run away from the wretched beast, and
all it's detriments, and deal with the bloat because its less damaging?
(I should also note that I heard no negative artifacts with the EQ - no
imaging change or high frequency issues). Finally – does anyone make an
affordable analog EQ that only affects the range below 300hz? (Or a
digital unit that is affordable and isn’t meant for subwoofers?)

"MD" wrote in message
...
From text I sent to Sterophile

I have been a subscriber for about 15 years. In that time I have
learned, and tried to put in practice, good room treatment techniques. I
use test CD's and a sound meter to aid in placement and I treat all the
room hot spots like first order reflection, echo flutter and deaden the
area behind my head (my Triangle Celius speakers sounds their best in a
spot that forces me to the rear wall- I have an odd room). What confuses
me is the double speak on tone controls and equalizers as well as
exactly which test tones I should use when running the tests.

I, too, have found it strange that no one has written definitively (or
pontificated , on the subject of use of equalizers. There appears to be no
literature on how professionals have used these, if at all, in small room
environments.

I have no problem hearing the difference between equalized and unequalized
performance, and neither should you. Equalizers are not subtle in effect
when used to correct large anomalies. What I have found, which is not unique
to my own experience, is that equalizers more often than not make the sound
worse, rather than better. According to the literature, this is because the
sound which impacts the ear directly from the speaker is perceived
differently from reflected sound, but an SPL meter makes no distinction,
summing direct and reflected sound to produce the reading.

I have a large collection of fancy, parametric equalizers, but I have
largely abandoned their use, with one exception, which is a set of Acoustat
electrostatic panels that seem to benefit from a 2dB boost at 1.2kHz.
Ironically, these speakers interact little with the room; it appears to be
the direct sound that requires adjustment. Equalizers are best at slight
modifications of the direct (anechoic) response of a speaker, but even this
need has declined, as modern speakers have more even response than older
designs.

A ten band equalizer is useless for the purpose, since room anomalies align
on octave boundaries. You need a parametric eq., or at least a twenty band
unit.

If you have a good parametric eq, straight tones should be used. The warble
tones are useful to operators of eqs with lesser resolution, by reducing the
number of measurements required to achieve optimal adjustment.

"Robert Morein" wrote in message
...


I have a large collection of fancy, parametric equalizers,
..........(insert Twilight Zone theme).........

"MD" wrote in message
...
From text I sent to Sterophile

I have been a subscriber for about 15 years. In that time I have learned,
and tried to put in practice, good room treatment techniques. I use test
CD's and a sound meter to aid in placement and I treat all the room hot
spots like first order reflection, echo flutter and deaden the area behind
my head (my Triangle Celius speakers sounds their best in a spot that
forces me to the rear wall- I have an odd room). What confuses me is the
double speak on tone controls and equalizers as well as exactly which test
tones I should use when running the tests.

On equalizers/tone controls. I can't count how many times I have read that
these are either the bane of our collective electronic existence or a
necessary tool to help make some recordings sound right (specifically tone
controls). On equalizers I read that they induce too many problems but
your magazine has recommended several of them (all in the digital domain I
believe).

Digital EQ is definitely better than analog EQ.

In my room I have several strong nodes below 300hz (as do most people I am
sure). I have a small dent at 50hz, huge plus ups at 60hz and 120hz and a
dip at about 250hz (Here is where the test tone confusion comes in. With
warble tones the aberrations are far lower. With straight tones I have a
16db shift from 120hz to 250hz - with warble tones the shift is about 5db.
Which am I to use?

Pink noise, not warble tones.

Seems to me warble tones are more
effective because the approximate the changes that occur in music?). After
studiously using my test gear/tones, set up programs, several suggestions
from professional sources (read in your mag and others) as well as
installing some room treatment (albeit none for bass control) I am left
with the predicament described. As far as I can tell room treatments,
designed to help in the low end, are not discriminate enough. While they
will tame my hot spots they will also negatively affect my dips(?). Using
a bass tone control won't work for basically the same reason. At the end
of the day (which I assure you is a grossly understated metaphor) I
decided to try a cheap 10 band EQ I had on hand (I would try the digital
products but they are way too expensive).

You should look into pro aduio EQ's as they are more affordable although
less accurate, they are still effective.

Utilizing the EQ and other associated items I was able to smooth out the
bumps, in both directions, to a very significantly measurable degree. Now
here's the rub. When I asked my daughter to help me A/B the difference
(which is easy with an EQ - one button) I had to work at hearing the
difference - more often than not. (I should note that I could go flat to
40hz and only 3db down at 31.5hz). While I was able to discern the
difference on some recordings (bass notes ended sooner - no bloat) it was
not a startling difference. As such is it "better" that I use the EQ to
settle the bloat or run away from the wretched beast, and all it's
detriments, and deal with the bloat because its less damaging? (I should
also note that I heard no negative artifacts with the EQ - no imaging
change or high frequency issues). Finally – does anyone make an affordable
analog EQ that only affects the range below 300hz? (Or a digital unit that
is affordable and isn’t meant for subwoofers?)

Here is a link to one such digital EQ, there are others available through
the same vendor and the brand name you find there. Check them out and
perhaps you will find somehthing that will help.

Be sure to read the desciptions carefully, as it is likely you will need
cables that you might not have.

With many units available below $300.00, it should be fairly easy to find
something.

The best units are most likely to be from RANE but will run $600.00 and up.
You can review their product line at their website,
http://www.rane.com/procat.html.

Good luck.

MD wrote:
From text I sent to Sterophile

I have been a subscriber for about 15 years. In that time I have
learned, and tried to put in practice, good room treatment techniques. I
use test CD's and a sound meter to aid in placement and I treat all the
room hot spots like first order reflection, echo flutter and deaden the
area behind my head (my Triangle Celius speakers sounds their best in a
spot that forces me to the rear wall- I have an odd room). What confuses
me is the double speak on tone controls and equalizers as well as
exactly which test tones I should use when running the tests.

On equalizers/tone controls. I can't count how many times I have read
that these are either the bane of our collective electronic existence or
a necessary tool to help make some recordings sound right (specifically
tone controls). On equalizers I read that they induce too many problems
but your magazine has recommended several of them (all in the digital
domain I believe).

In my room I have several strong nodes below 300hz (as do most people I
am sure). I have a small dent at 50hz, huge plus ups at 60hz and 120hz
and a dip at about 250hz (Here is where the test tone confusion comes
in. With warble tones the aberrations are far lower. With straight tones
I have a 16db shift from 120hz to 250hz - with warble tones the shift is
about 5db. Which am I to use? Seems to me warble tones are more
effective because the approximate the changes that occur in music?).
After studiously using my test gear/tones, set up programs, several
suggestions from professional sources (read in your mag and others) as
well as installing some room treatment (albeit none for bass control) I
am left with the predicament described. As far as I can tell room
treatments, designed to help in the low end, are not discriminate
enough. While they will tame my hot spots they will also negatively
affect my dips(?). Using a bass tone control won't work for basically
the same reason. At the end of the day (which I assure you is a grossly
understated metaphor) I decided to try a cheap 10 band EQ I had on hand
(I would try the digital products but they are way too expensive).
Utilizing the EQ and other associated items I was able to smooth out the
bumps, in both directions, to a very significantly measurable degree.
Now here's the rub. When I asked my daughter to help me A/B the
difference (which is easy with an EQ - one button) I had to work at
hearing the difference - more often than not. (I should note that I
could go flat to 40hz and only 3db down at 31.5hz). While I was able to
discern the difference on some recordings (bass notes ended sooner - no
bloat) it was not a startling difference. As such is it "better" that I
use the EQ to settle the bloat or run away from the wretched beast, and
all it's detriments, and deal with the bloat because its less damaging?
(I should also note that I heard no negative artifacts with the EQ - no
imaging change or high frequency issues). Finally - does anyone make an
affordable analog EQ that only affects the range below 300hz? (Or a
digital unit that is affordable and isn't meant for subwoofers?)

Like you I played for years with equalisation and so on.
Interestingly enough the dips and bumps you describe I have had also
and in three different rooms at that. The dip at 259 Hz. is almost
universal (used to be called "Allison effect") and even more noticeable
with planar speakers. It is hopelees to try to equalise it. Any
equalisation above + 3db results in audible distortion and very little
else. I finally followed the advice of an experienced audio system
installer and added and 8" speaker in a bandpass from about 50 to 300
hz. with unprecedented improvement. The bump at 60Hz is also very
common and esp. marked with a sinus wave signal.
I found the warble note source (Stereophile disk 2)
much more useful than the RTA sinus wave signal-very unstable and
disorienting.
I played with corner fabric bags and the acoustic
panels with little audible improvement (my supposedly universal
expectation bias proneness must be below average). You probably would
have to build up these sound absorbers all the way from the floor to
the ceiling to make much difference.
I had many analogue equalisers including the
"professional" ones. I could always "hear" them and it was a relief to
get rid of them. The digital Behringer "Ultracurve" was a discovery.
You can buy it now for a very moderate price (they cut it by half since
I bought mine). It appears not to deteriorate the sound- as long as you
do not exceed the 3db upwards correction!!-and in short I would not be
without it. As far as I know it is sold only through the "music'
retailers. It is said to be a copy of a much more expensive Mackie
professional. The American distributor in Seattle is very helpful.
Ludovic Mirabel
P.S. What a relief to get back to audio

MD wrote:
See previous message...."and isn't meant for subwoofers?)"

I should have added that I find the Radio Shack
Sound Power Level meter an inestimable help when equalising
It has to be calibrated. I used professional service
but the upper treble response is still exaggerated .
With this proviso I do not see how I could use
the eqaliser without it. It seems to me to be truer than Behringer's
own reading not to mention relying on my ears.
(Eg. my brain reads inadequate bass as exaggerated treble
and vice-versa.)
Behringer manual is terrible and could just as
well be written in Assyrian.
Ludovic Mirabel

----- Original Message -----
From:
Newsgroups: rec.audio.opinion
Sent: Tuesday, September 27, 2005 4:02 PM
Subject: Room correction help needed



MD wrote:
From text I sent to Sterophile

[snip]
I had many analogue equalisers including the
"professional" ones. I could always "hear" them and it was a relief to
get rid of them.

May I have a list, as far as you can recall, of equalizers you did not like?

The digital Behringer "Ultracurve" was a discovery.
You can buy it now for a very moderate price (they cut it by half since
I bought mine). It appears not to deteriorate the sound- as long as you
do not exceed the 3db upwards correction!!

Cut-only equalization, which is almost what you're doing, is said to be the
best. It is too easy to overdrive equipment while trying to fill the
infinite pothole